Radio signaling system



C. V. LOGWOOD RADIO SIGNALING SYSTEM Filed April 21, 1920 J rL fink/ my Mi 9 ATTORNEY I l I 45 source of high Patented F eb. 10,1925;

UNITED STATES PATENT OFFICE.

CHARLES VEYNE oewoon, on NEW ORK, 11. Y., ASSIGNOR TO DIE, FOREST mic 'rRLnrrroNRANn TELEGRAPH coMrANY, on NEW YORK, N. Y., a CORPORATION OF DELAWARE.

To allwh'omz'tmay concern:

Be it known that 1, CHARLES V. Loowoon, a citizen of the United States, residmg at New York, county and State of New i'York, have made a certain' new and use Invention in Radio Signaling Systems, which the following is a specification.

This invention relates to radio signaling systems, and more particularly to transmitting systems. r

' The object of the invention is to provide a transmitting system which is simple in circuit arrangement and efiicientin operatlOll.

16 A further object of the invention is to provide a radio signaling system wherein a source of high r uency oscillations 1s employed and the high frequency oscillations modulated in accordance with the signal to be sent, the circuits being so arranged that overmodulation is secured, i. e., the modulating signal current increases the power transmitted rather than decreases the same.

ii A further object of the invention is to provide a system of the character referred to articularly adapted for transmisslcn of ra i0 telephone messages where speech or audio frequency voice currents increase the power transmitted throughout the wave form thereof by the amount of modulatlon effected by the audio frequency voice cur rent. 7

, Further obd'ects of the invention will appear more fu ly' hereinafter.

The invention consists v the construction, combination,

relative arrangement of parts,

i the circuit arrangement em loyedin cOn-i nection therewith, all as wil be more fully hereinafter set forth, as shown by the accompan ing drawing, and finally pointed out in t e appended claims.

Referrin to the drawing, I em loy a location, and together with but which I have illustrated suitable source,

dynamo. I do not desire as a direct current ful v substantially in voltage 1 wh1ch may any the n a a RADIO SIGNALING SYSTEM,

to be limited or restricted in this respect, however, as the circuit arrangement and the elements employed in connection'therewith is to be regarded in the illustrative sense rather than in the limitin sense. The source of power 1, however has two distributing circuits, one of which passes from the source 1 through the choke coil 2 to-wire 3, ammeter 4, coil 3 5, inductance coil 6, to the plate electrode .7- ofoscillion 8, which for the purpose of :my invention has been illustrated as being of the evacuated tube type, havin locatedtherein filament, grid and plate e ectrodes of the usual construction, but I do not desire to be limited in this respect as any vessel having associated therewith a hot 2 and two or more cold electrodes each locatedat a relatively diflt'e'rent distance from the hot electrode and adapted to. be a source of hight, frequency oscillations, may be employed. The current path being described .fromthe source 1 passes from the plate -7 through the space ofthe oscillion 8, in the arrangement shown, to the filament electrode 9, and from there to the negative side of the source 1. The. other path of current from the sourcel is through the choke coil 2 to wire 10, ammeter 11, coil 12, choke coil 13, to plate electrode 14 of the oscillion 15, and thence to the filament electrode 16 of the oscillion 15 and through to the negative side of the current source 1 asbefore. The current also has a path from the coil 12, wire 17, through coil 18, wire 19, coil 20, choke coil 6, and plate electrode 7 of the oscillion 8, across to the filament9 thereof, and back to the negative side of the current source 1. Similarlyi to the plate electrode 14 o the oscillion 15,

thence tothe filament 16 thereof, back to egative side of the current source 1. ditional circuit path is provided current in the coil from the wire 19 to the positive terminal of a condenser 22, the negative terminal of which is connected to the negative terminal of a condenser 23, the positive of which is connected to the filament electrodes 16 and 9 of the respective oscillions 15 and 8. The-filaments 16 and 9 of the oscillions are lighted in the usual well known manner, for example, by means of a current source 24, as will be'readily apparent. When the circuit above described is connected to an oscillating circuit which may be traced from the plate electrode 14 through wire 24, condenser 25, inductance 26, condenser 27, ammeter 28 to earth 29, and similarly from the plate electrode 7, through wire 30 to the antenna earth circuit (the antenna of which is illustrated at 31), there is obtained a definite output of continuous high frequency current. The coils 20, 12, 5 and 18 are all wound on a common iron core, the coils 12 and 5, however, being wound oppositely so as to cause an opposed magnetic circuit through the iron core 33 common to all of the coils. The grid electrodes 34 and 35 of the oscillions 15 and 8 respectively are connected to each other through coils 36 and a common inductance coil 37 which is inductively associated with the signaling device, which may be either a microphone 38, included in clrcuit with the telephone coil 39, and a current source 40, or may be a signaling key 41 as shown. I preferably connect the inductance coil 37 which in the form shown is the secondary of an audiofrequency transformer to the negative side of the current source 1, the same being controlled by a key 42 connected in series with the high resistance 43. When, for example, the key 41 is closed a strong positive charge is imposed upon the grid electrode 34 of oscillion 15. There is also a strong negative charge on grid electrode 35. This has such an influence on the grid electrode 35 ofthe oscillion 8 that it almost stops the flow of current from the plate electrode 7 of oscillion 8 to the filament electrode 9 thereof.

en any circuit is suddenly robbed of its current the potential begins to rise to a igh value, and in this case it has a path through the coil 20 in a clockwise direction which passes into the condenser 22, and also through coil 18 to plate electrode 14 of oscillion 15 passing through the coil 18 in a clockwise direction. At this instant, the fields of the coils 12 and 5 are no longer in opposition, due to the stopping of the 5, as above described, on the plate electrode 7. us a strong magnetic field is built up in the coil 12.

is causes a rush of induced current through the coils 20 and 18. e current in the coil 20 is not strong because the flow would be to the plate electrode 7 of oscillion 8, which has already been stopped by a negative char e on the grid electrode 35 ofooscillion 8, w ile the current in the coil 18 passes into the condenser 22, condenser 23, to the filament electrodes of the oscillion, thereby making the plate electrode 14 of oscillion 15 negative and the filament 16 thereof positive. This would tend to stop the current flowing from the current source 1 to the line 10 by making'the plate electrode 14 negative. After the current in this branch (current source 1, line 10, coil 12, etc.) has been stopped flowing across the space between the plate and filament electrodes 14, 16, then the potential would rise and pass through the coil 12, coil 18, into the condenser 22, at the same time the imposed E. M. F. on the coil 5 would prevent any flow through the coil 20, coil 6, to the plate electrode 7 of oscillion 8. At this point the grid charge leaks off through the resistance 43 to the filament electrodes allowing currents to flow from plates 14 and 7 to the filaments 16 and 9 respectively, thus restor- I mg the circuit to its normal oscillating condition. but the condenser 22 excessive potential, starts leaking off the charge this condenser discharges into the plate electrodes 14 and 7 again, through the coils 20 and 18, as will be apparent, thus adding to the high potential of the current source 1. This causes momentarily an excessive rate of oscillating currents due to the actions of the grids 34 and 35 such as interrupting current in the primary circuit of the grids at 37 by a mechanical interrupter such as the key 41 or microphone 38. I provide small capacity condensers 50 and 51 connected between the respective grids 34 and 35 of the oscillions 15 and 8, and provide an adjustable tap connection 52 between the condensers and inductance 26. densers 27 can be from .0004 to ,009' Inf. While the condensers 22 and 23 are comparatively larger, for example, about from one to two mf., I shunt the terminals of the current source 1 with a condenser 55, which is provided to smooth out the commutator.

ripples. The coils 13, 6, and 36, are preferably air core choke coils which are provided to prevent high frequency currents from getting back into the circuit parts. With the arrangement thus described I have found that the operation is as above set forth. When the grid electrode 35 becomes negative it stops the current to a certain extent from the current source 1, line 3, coil 5, while the grid 34 of oscillion 15 is positive to a certain extent, but the increase of positive potential on the grid 34 does not greatly increase the flux in the circuit from the current source 1, line 10, and coil 12, and in consequence the induced current in the coils of the common core 33 is so great that it overpowers the efiect of increased positive has held an o and after the grid The conj' botential on the rid 34 relative to lllat spectiyely. W hen; the condenser {.22 dis-f chargesit-actually increases tl'iefrate of"r-adiation above normal radiation so thatfa't terrupting currentland/means foriincreasing l electrode 7 and'c'ause's the induccdcurrent inlthc coil to make the Plate electrode 14 .rcry negative, thereby stopping? the current as much asthc grid electrode 35 has stopped the current in the coil 5 and prevented same from reaching the filaments 16 and'9. When two indicating current meters, such'as is illustrated at 11 and 4, are put'in the cir cuits shown and the Morse key 41 orthe microphone 38 is operated the current drops in both of the oscillating audions or 05011- tions 15 and S at the same time. This causes a falling off of any radiating energy in accordance to the number of times the grid electrodes 34: and 35 of the respective oscillions become negatively and positively charged. When the current in the plate electrodes 14 and 7 have been stopped by grid potential changes the rising in potential throughout the circuit from the current source 1 will charge the condenser-22 to an excessive potential, and it will discharge back into the 'pl'ateele'ctrodesl4 and 7 only when; the grid. electrodes [34 and. j35'jc'eas'e to act} onthe latejelectrodesJ'and Tiethe end of each impulse'fro'm the grid :systcm this discharge from thecondenseraassists and adds potential to the'current source 1., In other words, when the signals are being sent the amount of the charge of the condenser 22 is added to the normal powergenerated b the system, and through the operation a ove described the systems instantly restores itself to normal radiation condition when no modulation is taking place, i. e., no signals are being sent. From the foregoing it will be seen that I have provided a system which may briefly be summed up by the statement. that when signals are being transmitted the power radiated is greater than normal rather than less than normal as is the case of transmitting systems heretofore proposed.

Many modifications and changes in detail will readily occur to those skilled in the art without departing from the spirit and scope of my invention as defined in the claims, therefore what I claim asnew and useful and of my own invention and desire to secure by Letters'Patent is,-

1. In an electrical signaling system,

means for generating oscillating currents,

and means for modulating the oscillating currents by and in accordance with the signals to'be transmitted,means for interrupting current and means for increasing thestrength of the transmitted currents by the I the strengthof' the oscillations dur ng the modulation of the oscillating currents.

2. In an electrical signaling system, means for generating and transmitting high frequency oscillations, means for modulating the oscillations by and in accordance with the signals to be'transinitted,ineans for interrupting current andmeans-fo'r increasing the strength of the-transmitted waves by the" modulation of the oscillating currents.

In a radio signaling system, a source of" high frequency currents, a source of low potentialsignal currents for modulating the high frequency currents by and in accordance with the signals to betransmitted, meansfor interrupting currents and means for increasing the strength of the transmitted waves during the modulation of the high frequency currents. 4. In an electrical signaling system, means for generating oscillating currents, and means for modulating the oscillating currents by and in accordance with the signals to be transmitted, means for interrupting current and means for increasing the strength of the transmitted currents by and in proportion to the modulation of the oscillating currents. 5

- 5. In an electrical signaling system, means gfori generating and transmitting high free .qucncy oscillations, 'means for modulating the oscillationsfby iand in accordance with the 'si'gnals to lie-transmitted, meansfor in -r the; "strength of the transmitted waves; by andin oscillating (currents.

of high frequency currents, a source of'lt'aw 1 potential signal currents for modulat ng the hlgh frequency currents by and in accordpropor'tionto the modulation ance with the signals to be 'transmitted,-[ I

means for interrupting ciu'rent and means for increasing the'strength of the transmitted waves during the modulation of the high frequency currents, and proportional- 1y to the low potential signal currents.

7, In a modulating system,'and in com bination with a source of high frequency oscillations and signal'controlled means formodulating the same, of means for increas ing the strength of theoscillations by and during the modulation thereof. i

8. In a modulating system, and in combination with a source of high frequency 0 scillations and signal controlled means for modulating the same, of means controlled solely by the signals tobe transmitted for increasing the strength of the oscillations during the modulation thereof.

9. In a'modulating system, and in combination with a source of high frequency oscillations and signal controlled means for modulating the same of means actuated by the signals to be transmitted for increasing modulation thereof.

10.- In a modulatingsystem, and in combination with a transmitting system and a source of high frequency oscillations having bination with a transmitting system and a source of high frequency oscillations having at least two paths controlled byelectron discharge, of means controlled by the signals to be transmitted, for stopping the flow of current through one path, means controlled thereby for building up and storing energy, and means for adding the energy stored up to the energy supplied said transmitting system.

12. In a modulating system, and in combination with a transmitting system and a source of oscillations having at least two paths therefor to said transmitting system, of means for stopping the flow of current through one of said paths, means controlled thereby for buildin up and storing energy, and means for addmg the stored energy to the energy supplied said transmitting system. I Y i 13. In a modulating system, and in combination withpa transmitting system and a source of oscillations having at least two paths therefor to said transmitting system, of means controlled by the signals to be transmitted, for stopping the flow of current through one path, means controlled thereby for building up and storing energy, and means for adding the energy stored up to the system.

14.' In a modulating system, and fincombination with a transmitting system and a source of'high frequency oscillations having at least two paths controlled by electron discharge, of means for stopping the flow of currentthrough one path, means controlled thereby for building up and storing energy and means for addin the energy stored up to the energy supfp 1ed said transmitting or system, and means restoring said system bination with a transmitting system and a source of high frequency oscillations having at least two paths controlled by electron discharge, of means controlled by the signals to be transmitted, for stoppingthe flow-of. current through one path, means controlled,

thereby for building up and storing energy,

and means for adding the energy store-dup to the energy supplied said, transmitting system, and means for restoring sald sys:-

tem to its normalcondition upon cessation of signals to be transmitted.

energy supplied said transmitting through one of said paths, means controlled thereby for buildin up and storing energy,

and means for adding the stored energy to the energy supplied said transmitting sys- 7 6 I toits normal condition upon cessation of tem, and means for restoring said system signals to be transmitted.

17. In a modulating system, and in combination with a transmitting system and a source of oscillations having atllleast two paths therefor to said transmitting system, of means controlled by the 'signals to 'be transmitted, for stopping the flow of current through one path, means controlled thereby for building up and storing energy, and means for adding the energy stored up to the energy suppliedsaid transmitting system, and means for restoring said system to its normal condition upon cessation of signals to be transmitted.

18. The combination with an antenna, of'

means for generating and supplying oscillating currents to said antenna including a cathode, grid and late electrodes, a source of current for said plate electrodes, means temporarily stopping the flow of current from one of said plate electrodes to the cathode, means rendered efi'ective thereby for building up and storing energy, and

-means for supplying the stored energy to or energy thereto.

the antenna additively to the normal supply 19. The combination with an antenna, of

means for generating and'supplying oscillating currents to said antenna including a cathode, grid and plate electrodes, a source of 5 current for said plate electrodes, means for I charging said grid electrodes with opposite I potentials, means controlled thereby for ilding' up and storing energy, and means for -supplying the stored energy to the antenna additively to the normal'snpply of energy thereto. a

20. The combination with an antenna, of

meansfor generating and supplying oscilto its normal condition upon cessation of signals to be transmitted. 15. In a modulating system, and in com-.

lating currents to said antenna including a cathode, grid and plate electrodes, a source of current for saidplate electrodes, means.

temporarily stopping the flow of current from one of said plate electrodes to the cathode, means rendered efiective thereby -for building up and storing energy, and

means forsupplying the. stored energy to the antenna additively to the normal supply with thesignals to be transmitted.

. 21. The combination with an antenna, of

means for generating" andsupplying 050i]:

lating currents to said antenna, including a cathode, grid and plate electrodes, a source of energy thereto during the modulation of of current for said plate electrodes, means the 1 oscillating currents by andin accordsfor charging said grid electrodes with opance with thesignals' to be transmitted. 1

posite potentials, means controlled thereby In testimony whereof I have hereunto set 5 for building up and storing energy, and. my hand on this 14th day of April, A. D.

means for sug lying the stored energy to 1920. the antenna a lively to the normal supply CHARLES VEYNE LOGWOOD. 

